1. Technical Field
The present invention relates generally to door security systems, and in particular to a door exit device providing reliable, controlled access through a doorway. In particular, the present invention relates to an apparatus, system, and method for controlling access through a movable barrier, such as a door, in which signal actuated latch retraction functionality is integrated with a delayed egress mechanism.
2. Description of the Related Art
Door exit devices, also referred to as panic exits or fire exits, are typically operated from the inside of an outward swinging door and are designed to provide building occupants fast and easy egress in an emergency. A door exit device generally comprises a manually actuated latch release mechanism releasing a door latch responsive to a relatively minimal force applied in the direction of egress travel through the doorway. The manually actuated release mechanism includes a readily accessible push pad or crossbar rail extending at least halfway across the width of the door.
With safety of building occupants as its primary function, a door exit device must always release the door latch, allowing exit without special access authorization or significant door operation knowledge. Any minimally sufficient horizontal push force applied to the outer vertical surface of a push pad type exit device retracts the latch bolt and releases the door to be opened. Several exit device designs have been designed and utilized including rim type, vertical rod, and mortise lock type devices.
For a variety of security reasons, it is often necessary to provide a delayed egress system with exit doors. Delayed egress systems are characterized by a locking mechanism that delays latch retraction, and consequently egress through the door, for a specified period of time (usually between 15 and 30 seconds) following an initial attempt to push-actuate the exit device. Delayed egress provides added door access control by preventing an unauthorized exit for the specified delay period while an alarm is sounded, enabling security personnel to react to the attempted exit. Common delayed egress mechanisms include a solenoid-controlled push pad locking bar or an electromagnetic locking device that prevent opening the door independent of exit device latch retraction. Delayed egress devices are utilized in retail and grocery stores, assisted living communities, hospitals, airports and other security-conscious establishments to provide a requisite level of door access controllability together with the safety features of an emergency exit device.
Electric latch retraction is another access control feature that may be implemented with exit devices. Electric latch retraction devices utilize a remote authorization/unlocking mechanism to control egress and/or ingress through the door. Electric latch retraction is less susceptible to tampering and is therefore preferred over external lever-actuated trim which can be more easily breached. Common electric latch retraction design includes a solenoid to retract the latch bolt. Such devices are common in airports, hospitals, office buildings, etc., and are typically activated by card readers, touch pads, electronic keys or other personal identification security devices.
Delayed egress is utilized with many exit device implementations to maintain a level of controlled access while also providing the emergency exit functionality required by safety regulations. It is sometimes the case, however, that the security features associated with delayed egress such as alarms as well as the delay mechanism itself, pose an obstacle or at least a significant inconvenience when the doorway in question must be accessed by authorized personal. Such authorized access is often provided using electric outside trim, locking or electric strikes. These mechanisms are vulnerable to security and vandalism problems.
There remains a need for an exit device apparatus, system and method that efficiently and reliably integrates electric latch retraction with delayed egress functionality. The present invention addresses such a need and other needs not addressed by the prior art.